1. Field of the Invention
The present invention relates to a valve device capable of maintaining safe pressure of a pressure vessel, particularly with regard to a valve device capable of maintaining safe pressure of a pressure vessel having a piston-typed safety valve set with high reliability, a coaxial structure of the valve device capable of reducing its volume, an engaging and hooking structure of the valve device contributing to precise and easy assembly of the valve device, having an opening and closing function for its valve body and having a wide range of practical applications.
2. The Related Arts
After cleaned water and wastewater are produced from traditional reverse osmosis water filter devices, wastewater is usually drained and cleaned water is conducted to flow through a three-way joint to be temporarily stored in a pressure vessel. When users are about take water, cleaned water from the pressure vessel is conducted to flow out to water outlets for users to take.
However, due to malfunction or some special reasons, the traditional reverse osmosis water filter devices cannot be stopped. Under such circumstances, it will cause excess pressure for the cleaned water. Also, because the pressure vessel has no any protective mechanism, the pressure vessel will be damaged or start to leak water.
Secondly, it is also very difficult to dismantle the pressure vessel when maintenance thereof is required. Not only water in entire pipelines needs to be removed, but also pressure of the pressure vessel needs to be released. The whole procedure is very complicated and troublesome.
In addition, if traditional ball valves are installed at a water inlet of the pressure vessel, it can only be manually switched to open or close, and cannot automatically determine whether the pressure of the pressure vessel is too large or not. If traditional diaphragm-typed pressure-releasing valves or protective valves are installed at the water inlet of the pressure vessel, their reliability is relatively low.
In view of the above, it is necessary to research and develop new technology to solve the above-mentioned disadvantages.